Six soldiers have been killed and 20 injured in attacks by Shia militants in the north of Yemen, officials say.

The attacks on military and security forces' bases in Saada province were led by prominent Shia militant Abel Malek al-Houthi, a statement said.

Details of which installations were attacked have not been released.

The security forces have clashed many times with northern Shias over the last three years, after a Shia uprising against the government in 2004.

That rebellion was led by Shia Muslim cleric Hussein al-Houthi, the brother of the man accused of leading this latest attack.

Hussein Badr Eddin al-Houthi died in the 2004 revolt, but forces loyal to him have continued with their anti-government campaign since.

US alliance

The rebels accuse the government of being too closely connected to Washington, which has supplied equipment and training for Yemen's security forces as part of its worldwide war on terror.

The Yemeni government says the Shias led by Abel Malek al-Houthi are trying to bring in Shia religious rule.

The statement from the Saada security committee relating to the latest violence gave no details of casualties among the Shias, whom it described as "saboteurs".

In it officials pledge to stamp out such violence, saying:

"The local authority and the armed and security forces in the province of Saada... will carry out their duties in preserving security and stability and ending these acts of sabotage carried out by these criminals".